Sahih Muslim Book 8, Hadith Number 3391.
Chapter: Permissibility of intercourse with a suckling lady and disapproval of ‘Azl.
Judaima daughter of Wahb al-Asadiyya (Allah be pleased with her) reported that she heard Allah’s Messenger (May peace be upon him) assaying: I intended to prohibit cohabitation with a suckling woman until I considered that the Romans and the Persians do it without any injury being caused to their children thereby. (Imam Muslim said: Khalaf reported it from Judamat al-‘Asadiyya, but the correct wording is what has been stated by Yahya.)